A barista examining the underside of a portafilter with a magnifying glass, diagnostic checklist visible on a tablet beside the machine

Symptom Diagnostic Guide

Contact Arco Support

Troubleshoot your Arco espresso machine with our diagnostic tree. Select your symptom and follow the steps to identify the cause and fix it yourself — or know when to call for professional service.

Data
{"symptoms": [{"id": "no-water-flow","symptom": "No water flows from the group head when brewing","severity": "high","possible_causes": [{"cause": "Water reservoir is empty or not seated properly","likelihood": "high","fix": "Refill the reservoir and ensure it clicks into place. Some machines have a float valve — press down on the reservoir firmly.","diy": true},{"cause": "Grind is too fine — puck is choking the machine","likelihood": "high","fix": "Remove the portafilter. If water flows freely from the group without the portafilter, your grind is too fine. Adjust 2-3 steps coarser.","diy": true},{"cause": "Solenoid valve is stuck closed","likelihood": "moderate","fix": "Backflush with cleaning solution to dissolve coffee oil buildup. If this does not resolve it, the solenoid may need replacement.","diy": true},{"cause": "Pump has failed","likelihood": "low","fix": "Listen for the pump sound when you activate the brew switch. If silent, the pump may have failed or lost electrical connection. Contact Arco service.","diy": false},{"cause": "Scale blockage in the boiler or thermosyphon tubes (E61 machines)","likelihood": "moderate","fix": "Perform a full descaling cycle. If severely blocked, a professional chemical flush may be required.","diy": true}],"when_to_call_service": "If water does not flow after verifying the reservoir, grind, and performing a backflush and descale."},{"id": "weak-espresso","symptom": "Espresso is thin, watery, or sour","severity": "low","possible_causes": [{"cause": "Grind is too coarse","likelihood": "high","